Ack, will you be experimenting with putting some kind of material on the underside of your VPI periphery ring? I would think that that may also be adding a sound to the table as it is metal and you seem to want to move away from that reflective material. You could place some dots of Isodamp or something every inch or so around the ring to lift it off the LP surface as long as it does not interfere with the raised arm/cartridge at the lead in groove. I assume you have raised your arm by a height equal to the thickness of your impedance matching material for your listening tests.
Turntable platter-LP impedance match
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Ack, will you be experimenting with putting some kind of material on the underside of your VPI periphery ring? I would think that that may also be adding a sound to the table as it is metal and you seem to want to move away from that reflective material. You could place some dots of Isodamp or something every inch or so around the ring to lift it off the LP surface as long as it does not interfere with the raised arm/cartridge at the lead in groove. I assume you have raised your arm by a height equal to the thickness of your impedance matching material for your listening tests.
I’ve been using sorbothane in the ring for years, for the reasons you state. The arm is adjusted as I experiment.
Just don't call it a mat
Three layers of Sorbothane/SPEC+ AP-UD1/Isodamp C-1002, ~7mm total, each layer is <2mm thick. The result is transformational, and I have never heard cello in here like this before; bass taughtness and lack of overhang taken to a much higher level; overall, much quieter than before, can tap the LP while playing and hear very little feedback. Added bonus: reduced feedback from the platter and bearing via the spindle/center weight, because the center weight no longer makes contact with the spindle - the thicker part of this spindle is now covered by this new interface, so one may say this spindle is "tapered" and the center weight's hole is now wider than the spindle.
I went through numerous iterations over two months, and this is likely the final interface for this 'table. The Isodamp does not really stick to the SPEC sheet, so an A/B with and without can be easily facilitated. Lesson learned: never buy a turntable with just a platter, a proper interface must be integrated by the manufacturer. This is really a lesson I learned from AJ Conti through the local dealer a while ago.
Three layers of Sorbothane/SPEC+ AP-UD1/Isodamp C-1002, ~7mm total, each layer is <2mm thick. The result is transformational, and I have never heard cello in here like this before; bass taughtness and lack of overhang taken to a much higher level; overall, much quieter than before, can tap the LP while playing and hear very little feedback. Added bonus: reduced feedback from the platter and bearing via the spindle/center weight, because the center weight no longer makes contact with the spindle - the thicker part of this spindle is now covered by this new interface, so one may say this spindle is "tapered" and the center weight's hole is now wider than the spindle.
I went through numerous iterations over two months, and this is likely the final interface for this 'table. The Isodamp does not really stick to the SPEC sheet, so an A/B with and without can be easily facilitated. Lesson learned: never buy a turntable with just a platter, a proper interface must be integrated by the manufacturer. This is really a lesson I learned from AJ Conti through the local dealer a while ago.
Nice to see someone giving mat construction a shot. I suggest you try cork on top, or in place of a layer. The cheaper the better because it has a more random pattern. Mine is from something at a home improvemet store I think. You may want to vacuum it and be mindful a static full record may pull some cork you'll need to destatic and brush off.
Really though I think if you're using weights then you want more mimimalist layers, because you are trying to couple. But if you want to decouple because the platter isn't low enough noise, then more layers and less weight should be more viable. Constrained layers will work in some frequency ranges but will be very limited for the simple fact that nothing pushes on the vinyl. For constraid layers it is imparative to have something between the ring and LP, if the ring makes contact with the platter.
Peter, the periphery ring won't reflect sound from the stylus that is as problematic. It is a fair distance and it couples the outer LP to the platter. You can use some kind of intermediary material but choose one that isn't very compressable if you do, as anything real soft will make the coupling poor.
Really though I think if you're using weights then you want more mimimalist layers, because you are trying to couple. But if you want to decouple because the platter isn't low enough noise, then more layers and less weight should be more viable. Constrained layers will work in some frequency ranges but will be very limited for the simple fact that nothing pushes on the vinyl. For constraid layers it is imparative to have something between the ring and LP, if the ring makes contact with the platter.
Peter, the periphery ring won't reflect sound from the stylus that is as problematic. It is a fair distance and it couples the outer LP to the platter. You can use some kind of intermediary material but choose one that isn't very compressable if you do, as anything real soft will make the coupling poor.
Agreed, and lest us not forget personal playback preference among individuals + listening rooms + associated equipment will never achieve any real level of "standardization".
High End Audio reproduction is an art form with many varying tastes and flavors. Playback priorities will vary. Simply put, if you like the way something sounds and makes you feel, then it's right for you.
Right, well stated!
I run a VPI Mk V platter on my TNT. It is probably a couple of decades old by now and is Delrin over stainless steel weighing in at around 20 pounds. I find that in my system, it sounds wonderful and is far and away the best sounding platter I have tried.
The rage at VPI seems to be the all aluminum Classic platter but when I see a lot of discussion on the VPI forum concerning mat materials for it I have to wonder why, so I have not been inclined to move on from the Mk V.
The rage at VPI seems to be the all aluminum Classic platter but when I see a lot of discussion on the VPI forum concerning mat materials for it I have to wonder why, so I have not been inclined to move on from the Mk V.
I can fully agree w the sentiment on not playing lps directly off a bare metal platter.
Going from lp sound off my Al platter v off the Delrin cones attached to the same platter is night and day.
Going from lp sound off my Al platter v off the Delrin cones attached to the same platter is night and day.
Hi Peter, a couple of things.
I believe Vic the designer still needed high mass in the platter to be able to use high torque/flywheel effect, and this would have been impossible had he gone for 100% Delrin (too light). Indeed he did have a lightweight acrylic platter option, and it fell short on some aspects of SQ.
Additionally Vic may be the only designer of a modern tt where he has eschewed all securing of the lp - no clamp, no weight, no periphery ring, no vacuum hold down, and also minimal contact w support under by means of individual points, not fully to platter. He's v much of the opinion that vinyl is easily stressed by holding vinyl down, and in effect prefers the lp to be allowed to breathe. He realises that there are more arguments against this approach than in favour of it, but bullishly has stuck to his opinion.
I believe Vic the designer still needed high mass in the platter to be able to use high torque/flywheel effect, and this would have been impossible had he gone for 100% Delrin (too light). Indeed he did have a lightweight acrylic platter option, and it fell short on some aspects of SQ.
Additionally Vic may be the only designer of a modern tt where he has eschewed all securing of the lp - no clamp, no weight, no periphery ring, no vacuum hold down, and also minimal contact w support under by means of individual points, not fully to platter. He's v much of the opinion that vinyl is easily stressed by holding vinyl down, and in effect prefers the lp to be allowed to breathe. He realises that there are more arguments against this approach than in favour of it, but bullishly has stuck to his opinion.
This is a very interesting and complex issue
As Folsom has indicated depends firstly if you wish to couple or not to the platter
Vacuum hold down represents one extreme of coupling, weights and peripheral clamps are others
Marc s turntable represents the other extreme minimal coupling
If you have a noisy motor system coupling to this may be undesirable
Any mat would have some damping qualities though these will be under damped and limited in frequency range
Claearly damping of resonances is the most important aspect
Poor coupling with the platter will lead to little transfer of vibration into the turntable and most energy will be reflected back, though in a high damping material this will be dissipated over time
There is no reason a metal platter cannot be used, and the degree of coupling and amount of slip will determine vibrational transfer and reflected vibration, and material type and density
As it is denser than vinyl and a metal the amplitude and speed will be different
Highly damped material will propagate vibration slower than less damped material eg rubber versus aluminium
Platter interfaces will need some way of dealing with the vibration transferred to them
In addition there is the vibration of the platter system into the record
Thus a poor coupling system will lead to less transfer from the turntable
So ultimately in any given turntable the optimum material will be a favourable combination of all these factors
One cannot make a categorical statement for a given turntable system that will necessarily be true for all.....
As Folsom has indicated depends firstly if you wish to couple or not to the platter
Vacuum hold down represents one extreme of coupling, weights and peripheral clamps are others
Marc s turntable represents the other extreme minimal coupling
If you have a noisy motor system coupling to this may be undesirable
Any mat would have some damping qualities though these will be under damped and limited in frequency range
Claearly damping of resonances is the most important aspect
Poor coupling with the platter will lead to little transfer of vibration into the turntable and most energy will be reflected back, though in a high damping material this will be dissipated over time
There is no reason a metal platter cannot be used, and the degree of coupling and amount of slip will determine vibrational transfer and reflected vibration, and material type and density
As it is denser than vinyl and a metal the amplitude and speed will be different
Highly damped material will propagate vibration slower than less damped material eg rubber versus aluminium
Platter interfaces will need some way of dealing with the vibration transferred to them
In addition there is the vibration of the platter system into the record
Thus a poor coupling system will lead to less transfer from the turntable
So ultimately in any given turntable the optimum material will be a favourable combination of all these factors
One cannot make a categorical statement for a given turntable system that will necessarily be true for all.....
When I use the stainless upper platter option on the AF1... I prefer the sound of bare metal. One can damp too much killing the brilliance of the sound and over homogenizing it. Horses for courses!
The only reason I use a very thin leather mat on the AS2000 is to keep the spinning platter from micro scratching my vinyl during flips....I keep it spinning constantly during the listening session. With the AF1 and vacuum hold down, I stop the platter for every flip.
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I agree with this as it matches my experience with my NGS and its integrated copper mat.
Cheers, Joe
So I have some good news and some bad news. The good news is that my interface works wonders, when the LP is coupled to it. The bad news is that... concave/convex LPs are a pain in the behind - UGH! The bass articulation difference between Side A and side B can be staggering. And this says one thing: must get a turntable with a proper interface plus vacuum hold-down. Anyone selling a AF-1 ?!?!?
On another note, yes, coupling is what I am after; and when the LP is coupled to the interface, I get more feedback when I tap the turntable plinth than when I tap the LP surface while playing - by orders of magnitude. One of the goals with this design was to not have an overly soft interface, hence the damped solid aluminum SPEC "sheet" (as they call it) between the sorbothane and Isodamp.
On another note, yes, coupling is what I am after; and when the LP is coupled to the interface, I get more feedback when I tap the turntable plinth than when I tap the LP surface while playing - by orders of magnitude. One of the goals with this design was to not have an overly soft interface, hence the damped solid aluminum SPEC "sheet" (as they call it) between the sorbothane and Isodamp.
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So I have some good news and some bad news. The good news is that my interface works wonders, when the LP is coupled to it. The bad news is that... concave/convex LPs are a pain in the behind - UGH! The bass articulation difference between Side A and side B can be staggering. And this says one thing: must get a turntable with a proper interface plus vacuum hold-down. Anyone selling a AF-1 ?!?!?
On another note, yes, coupling is what I am after; and when the LP is coupled to the interface, I get more feedback when I tap the turntable plinth than when I tap the LP surface while playing - by orders of magnitude. One of the goals with this design was to not have an overly soft interface, hence the damped solid aluminum SPEC "sheet" (as they call it) between the sorbothane and Isodamp.
Look for an Audio Technica AT-666 vacuum platter.
And this says one thing: must get a turntable with a proper interface plus vacuum hold-down. Anyone selling a AF-1 ?!?!?
After all the years of hearing Basis turntables at Goodwins, did you ever consider buying one of their vacuum hold down tables? Basis has always impressed me, and I seriously considered the brand before settling on SME.
That's how severe some LPs are; they all happen to the older, thinner 120-140g; the weight and ring cannot possibly be the same as a vacuum hold down, and is also the reason why we have LP flatteners.
For reference, here's the Basis super platter, mounted on the Inspiration; that interface surface is basically harder than mine, which is already pretty hard
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